Review of Critical Care Medicine
Surgery MCQs (Arterial,Venous Disorders &
Lymphatic Disorders)
Posted by Dr KAMAL DEEP on May 31, 2011
Commonest cause of A-V fistulae is – (AI 88)
a) Congenital b) Traumatic
c) Surgical creation d) Tumour erosion
Congenital A-V fistulas in the thigh will be associated with all except – (PGI 89)
a)Increased cardiac output
b)Increased skin tempreture
c)Gigantism of limb
d)Superficial venous engorgement
Continuous murmur is not found in- (AIIMS 89)
a)PDA
b)Systemic A-V fistula
c)Rupture of sinus of valsalva
d)Double outlet right ventricle
AV fistula leads to all except – (AIIMS 98)
a)Sinus tachycardia
b)Increased preload
c)Cardiac arrythm ias
d)Increased cardiac output
AV fistula causes – (PGI 98)
a) dec Diastolic b) inc Venous return
c) dec Venous congestion d) inc Systolic fillin
Nicoladoni branham sign is – (PG198)
a)Compression cause bradycardia
b)Compression cause tachycardia
,c)Hypotension
d)Systolic filling
True regarding AV fistula is – (PGI 02)
a)Leads to cardiac failure
b)Causes local gigantism
c)Can cause ulcers
d)Cause excess bleeding on injury
e)Closes spontaneously
Complications arising out of A – V fistula done for renal failure include the following
EXCEPT –
a)Infection (Jipmer 03)
b)Thrombosis
c)High output cardiac failure
d)Necrosis of the distal part
Ans. is ‘d’ i.e., Necrosis of the distal part [Ref Sabiston 161"/e p.1456; Love & Bailey 246/e p.950 ;
23"//e p.23]
Pulsating varicose vein in a young adult is due to-
a)Arteriovenous fistula (AIIMS 92)
b)Sapheno femoral incompetence
c)Deep vein thrombosis
d)Abdominal tumour
In Osler Weber Rendu syndrome A.V. fistulas occur.
The clinical features depend on the location and size of the fistula. Frequently, a pulsatile
mass is palpable, and a thrill and bruit lasting throughout systole and diastole are present
over the fistula. With longstanding fistulas, clinical manifestations of chronic venous
insufficiency, including peripheral edema; large, tortuous varicose veins; and stasis
pigmentation become apparent because of the high venous pressure. Evidence of ischemia
may occur in the distal portion of the extremity. Skin temperature is higher over the
arteriovenous fistula. Large arteriovenous fistulas may result in an increased cardiac output
with consequent cardiomegaly and high-output heart failure.
The diagnosis is often evident from the physical examination. Compression of a large
arteriovenous fistula may cause reflex slowing of the heart rate ( Nicoladoni -Branham sign).
Physiological effect
The combination of an uncontrolled leak from the high-pressure arterial system and an
enhanced venous return and venous pressure results in an increase in pulse rate and cardiac
output. The pulse pressure is high if there is a large and persistent shunt. Left ventricular
enlargement and, later, cardiac failure occur. A congenital fistula in the young may cause
overgrowth of a limb. In the leg, indolent ulcers may result from relative ischaemia below the
short circuit.
Clinical signs
,Clinically, a pulsatile swelling may be present if the lesion is relatively superficial. On
palpation, a thrill is detected and auscultation reveals a buzzing continuous bruit. Dilated
veins may be seen, in which there is a rapid blood flow. Pressure on the artery proximal to the
fistula causes the swelling to diminish in size, the thrill and bruit to cease, the pulse rate to
fall [known variously as Nicoladoni’s (1875) or Branham’s (1890) sign] and the pulse pressure
to return to normal.
AV (arteriovenous) fistulas are recognized as the preferred access method. To create a fistula,
a vascular surgeon joins an artery and a vein together through anastomosis. Since this
bypasses the capillaries, blood flows rapidly through the fistula. One can feel this by placing
one’s finger over a mature fistula. This is called feeling for "thrill" and produces a distinct
‘buzzing’ feeling over the fistula. One can also listen through a stethoscope for the sound of
the blood "whooshing" through the fistula, a sound called bruit.
Fistulas are usually created in the nondominant arm and may be situated on the hand (the
‘snuffbox‘ fistula’), the forearm (usually a radiocephalic fistula, or so-called Brescia-Cimino
fistula, in which the radial artery is anastomosed to the cephalic vein), or the elbow (usually a
brachiocephalic fistula, where the brachial artery is anastomosed to the cephalic vein). A
fistula will take a number of weeks to mature, on average perhaps 4–6 weeks. During
treatment, two needles are inserted into the fistula, one to draw blood and one to return it.
, The advantages of the AV fistula use are lower infection rates, because no foreign material is
involved in their formation, higher blood flow rates (which translates to more effective
dialysis), and a lower incidence of thrombosis. The complications are few, but if a fistula has a
very high blood flow and the vasculature that supplies the rest of the limb is poor, a steal
syndrome can occur, where blood entering the limb is drawn into the fistula and returned to
the general circulation without entering the limb’s capillaries.
Maximum tourniquet time for the upper limb is –
a) 1/2 hour b) 1 hr (JIPMER 87)
c) 1-1/2 hrs. d) 2 hrs
e) 2-1/2 hrs
Sabiston:- Tourniquet Application:- The tourniquet is used to provide a bloodless field so
that clear visualization of all structures in the operative field is obtained. Penrose drains,
rolled rubber glove fingers, or commercially available tourniquets can be used on digits.
Great care must be taken in using any constrictive device on digits because narrow bands
cause direct injury to underlying nerves and digital vessels. With the use of an arm
tourniquet, the skin beneath the cuff must be protected with several wraps of cast padding.
During skin preparation, this area must be kept dry to prevent blistering of the skin under an
inflated cuff over moist padding. The cuff selected needs to be as wide as the diameter of the
arm. Standard pressures used are 100 to 150 mm Hg greater than systolic blood pressure. The
cuff is deflated every 2 hours for 15 to 20 minutes (5 minutes of reperfusion for every 30
minutes of tourniquet time) to revascularize distal tissues and to relieve pressure on
nerves locally before reinflating the cuff for more extensive procedures. Exsanguination of
the extremities is performed by wrapping the extremity with a Martin’s bandage in all cases,
except those involving infection or tumors. In these latter cases, because of the possibility of
embolization by mechanical pressure, exsanguination by bandage wrapping needs to be
avoided. Simple elevation of the extremity for a few minutes before tourniquet inflation
suffices.
Bailey:- Tourniquet:- A bloodless field is essential for accurate surgery. A well-padded
tourniquet above the elbow, inflated to 75 mmHg pressure over the systolic blood pressure, is
usually satisfactory. The time should not exceed 2 hours. An Esmarch bandage or a rubber-
tube exsanguinator are effective, but should be avoided for tumour or infection cases lest the
pathology is spread systemically. In the finger, a tourniquet can be made by placing a sterile
glove on the patient, snipping off the tip and then rolling the glove down to the base of the
finger.
Thromboembolism after pelvic surgery is usually from the veins – (A189)
a) iliac b) Calf
c) Femoral d) Pelvic
An obese patient develops acute oedematous lower limb following a Pelvic surgery. Deep
vein thrombosis is suspected . The most useful investigation in this case would be – (UPSC
2002)
